1. Field of the Invention
The present invention relates to an apparatus and method for coupling an automated attendant to a telecommunications system. More specifically, the present invention relates to a telecommunications switching apparatus that can be used in conjunction with an automated attendant and which is capable of transferring incoming telephone calls answered by the automated attendant to any of a plurality of stations while enabling the automated attendant to monitor the status of the incoming calls continuously.
2. Description of the Related Art
Many businesses subscribe to a plurality of telephone numbers in order to handle a large amount of incoming telephone calls. Typically, these multiple telephone numbers require that the business have access to several trunk or central office (CO) lines which each provide service for a specific number.
Conventionally, a business would utilize telephones that are each capable of being connected to any of the plurality of trunk lines. For example, in a drug store, bank, or any typical business, each telephone would be connected to all of the CO lines to which the business subscribes. Each telephone would have a plurality of buttons, each of which is assigned a specific telephone number corresponding to the subscriber number being handled by one of the CO lines.
Assuming, for example, that the business subscribes to five telephone numbers, five trunk lines would enter the business, and each of those trunk lines would be coupled to a button on each of the telephones in the business. Hence, if a call were to come in on line 1, the button on each of the phones corresponding to that line would light up, and all of the phones would ring. A person could then answer the call coming in on that line by depressing the lighted button and picking up the receiver.
However, a drawback of this conventional system is its inability to transfer calls to other lines. For example, if a call were to come in on line 1 that was meant for a person at telephone station 3 but was answered by a person at telephone station 1, the person at telephone station 1 would have to inform the person at telephone station 3 that person has a telephone call. Typically, this would be accomplished by a paging system in which the person answering the call would page the person for which the call was meant. The person for which the call was meant would then need to depress the button on his or her telephone corresponding to the line on which the call was being received.
Hence, this type of system would result in a disruption of the person at telephone station 1 even though the call was not meant for that person. Also, everyone in the business would constantly have to listen to the pages to ascertain whether they were meant to receive a particular call. Furthermore, this type of system afforded little or no privacy because a person at any telephone could easily eavesdrop on any of the lines.
In order to improve this type of telephone system by enabling the system to have the capability of transferring calls being received on any of the trunk lines to a particular line designated to a particular phone or station, a private branch exchange (PBX) was developed as shown, for example, in FIG. 24. A PBX is a programmable device which includes a plurality of input ports to which are coupled the plurality of trunk lines, and a plurality of output ports which are coupled to the telephone stations in the business.
The PBX can be controlled, for example, by an operator. Hence, if a call comes in on the first trunk line, for example, the PBX can answer that call and then forward that call to the operator. The operator can then control the PBX to transfer that call to another line (e.g., the third station line), so that the telephone allocated to receive calls on that third station line would ring. PBXs also afford the system the capability of servicing a number of stations different from the number of trunk lines.
For example, in a 4xc3x978 PBX system, four trunk lines can be input to the PBX, while eight station lines can be output from the PBX. Hence, the PBX can be controlled to transfer calls being received on any one of those four trunk lines to any one of the eight station lines.
A typical PBX of the type described above can further be programmed to perform many tasks in addition to transferring incoming calls. For example, the PBX can be programmed to ring telephones at several of the station lines in response to an incoming call. Also, the PBX is capable of permitting connections between telephones at various stations. Hence, if a person at one station wishes to call a person at another station, that person can use an xe2x80x9cinside linexe2x80x9d which the PBX provides in order to make the connection.
Furthermore, the PBX is capable of screening a telephone number that is being dialed at one of the station phones. For example, particular stations phones may be prohibited from dialing long distance numbers. Accordingly, the PBX is capable of determining when an attempt is made to dial a long distance number from one of those stations, and will prevent such a call from being made.
It is also important to note that a PBX is typically used with a system having telephones that are incapable of performing dialing functions themselves. In such a system, the PBX performs the dialing functions in accordance with signals received by those types of telephones which are connected to the PBX.
In a further attempt to streamline a conventional telephone system, an automated attendant has been developed as shown, for example, in FIG. 25. An automated attendant is used in conjunction with a PBX to perform the tasks that would be performed by a human operator, such as taking messages and controlling the PBX to transfer calls to any number of stations.
It is noted that an automated attendant does not have the capability of transferring calls on its own. Hence, in conventional systems, an automated attendant must be used in conjunction with a PBX. Therefore, if a conventional telephone system, such as that described above which is serviced by a plurality of telephone lines, is modified to have automated attendant capabilities, a PBX must also be employed in the system even if the additional functions provided by a PBX are not used.
For example, in order to enable a conventional telephone system to be used with an automated attendant, Microlog Corporation has developed a front-end module, an example of which is shown specifically in FIG. 25. The front-end module is a standard PBX, however, the front-end module PBX is only used to give the system call transferring capabilities that are not provided by an automated attendant alone. The trunk lines (e.g., 8 trunk lines) are input to the input ports of the front-end module PBX, and 8 of the output ports are dedicated for use by the automated attendant. It is noted that in a system having 8 trunk lines which originally were connected to each of 8 station phones, an 8xc3x9716 PBX having 8 input ports and 16 output ports must be used. The 8 input ports are connected to the trunk lines and 8 of the output ports are connected to the voice ports of the automated attendant. The other 8 output ports of the PBX are connected to the 8 stations as illustrated.
A call coming in on any of the trunk lines (e.g., trunk line 1) will be answered by the PBX, which then transfers the call to the automated attendant. The automated attendant will typically play a message to the caller which gives the caller several options, such as the opportunity to leave a message or to press a key on the caller""s telephone keypad in order to instruct the automated attendant to perform a certain function (e.g., to control the PBX to transfer the call to one of the station lines).
However, several problems exist with this type of front-end module PBX and automated attendant system. For example, because PBXs are capable of performing many tasks in addition to call transferring as discussed above, PBXs typically are very complex and consequently, very expensive. Therefore, a proprietor of a small business may not wish to incur such expense in order to update their telephone system to have automated attendant capabilities. In other words, if the proprietor merely wants to update the telephone system of the business to have automated attendant capabilities, the type of system described above which uses a PBX as a front end module is impractical from a cost standpoint because the proprietor is essentially paying for the additional capabilities made available by the front-end module PBX even though the proprietor has no desire to employ those features in the business.
Furthermore, due to the nature of the PBX system, the automated attendant is rendered incapable of determining the status of an incoming call. An automated attendant monitors the status of an incoming call (i.e., to detect hang-up by the caller) on a trunk line by monitoring the line status of that trunk line (i.e., the DC loop current component of the telephone signal from the caller""s station). If a call is active on a trunk line, that trunk line will have a certain DC loop current. When the caller hangs up to release that trunk line, the loop current will disappear. However, because a PBX isolates the loop current of the trunk lines from the automated attendant, the automated attendant used in conjunction with a PBX cannot detect the loop current of the trunk lines to monitor the status of the incoming calls.
Hence, in the typical automated attendant and PBX system, such as the front end module type system described above, if a caller instructs the automated attendant to control the PBX to transfer a call to a particular station line and then hangs up, the automated attendant will continue its processing operations for a certain period of time after hang up. As a consequence, the automated attendant does not allow the PBX to release the trunk line on which the call was incoming, and furthermore, does not release the station line to which the call was being transferred. Hence, no calls could come in on that particular trunk line during this period, and no calls could be made on that station line.
In an attempt to eliminate this drawback, loop current detectors have been coupled to the trunk lines as shown in FIG. 25, and are configured to provide signals to the automated attendant indicating the status of the loop current on the trunk lines. The automated attendant can determine from this loop current whether the caller on the trunk line has hung up. However, this arrangement does not eliminate the need for a PBX to implement call transfers.
Furthermore, because the PBX answers the incoming call, this arrangement prevents the automated attendant from performing caller-ID functions. An automated attendant will detect a caller-ID signal that is present between the first and second ring signals of an incoming call. However, because the PBX answers the incoming call and hence, isolates the call from the automated attendant, the automated attendant does not receive this caller-ID signal.
Accordingly, a need arises for a system that is capable of enabling an existing telephone system to be used with an automated attendant and have call transferring capabilities without requiring the use of an expensive PBX. This system also should allow the automated attendant to receive the incoming calls, thereby enabling the automated attendant to detect and process the caller-ID signal. The system should further enable the automated attendant to monitor the status of an incoming call when the call is being transferred and throughout the entire period when communication is established between the caller and a called party, to thus enable the automated attendant to detect for hang-up by the calling party at any time.
An object of the present invention is to provide an apparatus for coupling an automated attendant to a telecommunications system which provides call transferring capabilities without the use of a PBX.
Another object of the present invention is to provide an apparatus which enables the automated attendant to receive and answer the incoming calls. The apparatus thus enables the automated attendant to detect and process a caller-ID signal and continuously monitor the status of a call being received on the trunk lines of the telecommunications system when the apparatus is being controlled to transfer calls and also while communication is occurring between the trunk lines and a called party line which is serviced, for example, by one of the station lines.
A further object of the present invention is to provide an apparatus that has a switching network that operates in conjunction with an automated attendant, such that the apparatus operates to essentially isolate the switching network from the audio signal component of an incoming call when the automated attendant is handling the incoming call and further, which operates to essentially isolate the automated attendant from the audio signal of the incoming call while enabling the automated attendant to monitor the loop current of the line on which the incoming call is being received when the incoming call is being routed through the switching network.
Another object of the present invention is to enable an incoming call that is being received on one of the trunk lines to be routed through the switching network and out to an external station over another one of the trunk lines.
A further object of the present invention is to enable system control capabilities from one of the stations attached to the station lines and to provide for paging capabilities from the automated attendant.
Another object of the present invention is to provide a system which is adapted to be coupled to an existing telephone system, and which monitors itself continuously for abnormalities such as loss of power, loss of control signals, and so on, so as to reestablish the original connections between the trunk lines and station lines of the existing system in the event of such an abnormality.
The above objects are substantially achieved by providing an apparatus including a plurality of line ports which are adapted to be coupled to a plurality of trunk lines, respectively, of an existing telephone system, and a plurality of ports which are adapted to be coupled to the voice ports, respectively, of an automated attendant system. The apparatus further includes a switching network which is controllable to establish communication between any of the trunk lines and any of a plurality of station line ports that are adapted to be coupled to a plurality of telephone stations, respectively. The apparatus further includes an isolation circuit which is operable to essentially isolate the switching network from the AC audio portion of a signal being received on one of the trunk lines when the signal is being handled by the automated attendant, and which is further operable to essentially isolate the automated attendant from the AC portion of the signal when the signal is routed through the switching network while allowing the automated attendant to monitor the DC loop current of the trunk line on which the signal is being received.
The apparatus further includes a plurality of detector circuits which are capable of detecting the status of the station lines prior to establishing communication between a trunk line on which a call is being received and a particular station line. The apparatus also includes a port which is adapted to be coupled to a station which is capable of providing control communication to the automated attendant via a designated station line. Furthermore, the switching network is capable of providing communication between a designated station or automated attendant port and an output port of the apparatus which adaptable to be connected to a sound system that is capable of outputting audio signals (e.g., paging) based on the signals input at the designated station.